Electric Vehicle Savings Calculator
Switching from a gasoline-powered car to an electric vehicle (EV) can significantly reduce fuel costs and carbon emissions. This calculator compares the annual fuel cost of driving a gas car against the electricity cost of an equivalent EV, using your actual miles driven, gas price, electricity rate, and vehicle efficiency figures. The EPA rates EV efficiency in kilowatt-hours per 100 miles, so entering your specific vehicle's EPA rating gives the most accurate result. CO2 calculations use the EPA figure of 8.89 kg of CO2 per gallon of gasoline burned, and the EIA 2023 national average grid emission factor of 0.386 kg of CO2 per kilowatt-hour of electricity generated. Because the US grid is a mix of fossil and renewable sources, EVs produce less CO2 than gas cars in every US state, with the largest reductions in states with cleaner electricity grids. This calculator covers fuel costs only. Additional EV advantages include lower maintenance costs (no oil changes, fewer brake replacements due to regenerative braking) and potential federal and state purchase incentives. Enter your figures below to see your personalised annual fuel savings and CO2 reduction.
Annual fuel savings switching to EV: -- with a CO2 reduction of -- kg/year.
How the EV savings calculation works
The calculation compares cost per mile for each vehicle type, then scales to annual figures based on miles driven. CO2 figures use official EPA and EIA emission factors.
Gas cost per mile ($) = gas_price / mpg
EV cost per mile ($) = electricity_rate × ev_kwh_per_100mi / 100
Annual gas cost ($) = annual_miles × gas_cost_per_mile
Annual EV cost ($) = annual_miles × ev_cost_per_mile
Annual savings ($) = annual_gas_cost - annual_ev_cost
Gas CO2 (kg/yr) = (annual_miles / mpg) × 8.89
EV CO2 (kg/yr) = annual_miles × ev_kwh_per_100mi / 100 × 0.386
Worked example
12,000 miles/year, 28 MPG gas car, $3.50/gal, 3.5 kWh/100 mi EV, $0.16/kWh:
- Gas cost per mile = $3.50 / 28 = $0.125/mile
- EV cost per mile = $0.16 × 3.5 / 100 = $0.0056/mile
- Annual gas cost = 12,000 × $0.125 = $1,500.00
- Annual EV cost = 12,000 × $0.0056 = $67.20
- Annual savings = $1,500.00 - $67.20 = $1,432.80
- Gas CO2 = (12,000 / 28) × 8.89 = 3,810.00 kg/year
- EV CO2 = 12,000 × 3.5 / 100 × 0.386 = 161.88 kg/year
EV efficiency ratings by vehicle type
The EPA publishes official efficiency ratings for every EV sold in the US at fueleconomy.gov. Use your specific vehicle's rating for the most accurate result.
| Vehicle Type | Typical EPA Rating (kWh/100 mi) |
|---|---|
| Compact car (e.g., Chevy Bolt, Nissan Leaf) | 3.0 to 3.5 |
| Mid-size sedan (e.g., Tesla Model 3, BMW i4) | 3.5 to 4.0 |
| Mid-size SUV (e.g., Tesla Model Y, Ford Mustang Mach-E) | 3.5 to 4.5 |
| Full-size SUV and truck (e.g., GMC Hummer EV, Rivian R1T) | 4.5 to 6.5 |
Source: EPA fueleconomy.gov model year 2024 data. Find the exact rating for any model at fueleconomy.gov.
EV savings calculator: frequently asked questions
How much does it cost to charge an EV versus filling up a gas car?
It depends on your electricity rate and gas price, but EVs are typically much cheaper to fuel. At a national average electricity rate of $0.16/kWh and 3.5 kWh per 100 miles of EV efficiency, the energy cost is about $0.056 per mile. A gas car getting 28 MPG at $3.50 per gallon costs about $0.125 per mile. The EV is roughly 55% cheaper per mile to fuel in this example. Home charging overnight on off-peak rates can reduce EV costs further.
What does kWh per 100 miles mean for an EV?
kWh per 100 miles is the EPA's standard efficiency rating for electric vehicles, analogous to MPG for gas cars. A lower number means a more efficient EV. The EPA publishes official ratings for every EV model at fueleconomy.gov. Compact EVs like the Chevy Bolt typically rate around 3.5 kWh/100 miles, while larger SUVs and trucks may rate 4.0 to 5.0 kWh/100 miles. Real-world efficiency varies with speed, temperature, and use of climate control.
Does this calculator include the EV federal tax credit?
This calculator focuses on ongoing fuel cost savings and does not include the federal EV tax credit, which can be up to $7,500 for new qualifying vehicles under the Inflation Reduction Act (IRS Form 8936). Including the credit would further improve the EV's financial position. For the full picture, compare the purchase prices and available credits, then add the annual fuel savings from this calculator.
How is CO2 reduction calculated for EVs?
Gas car CO2 is calculated using the EPA figure of 8.89 kg of CO2 per gallon of gasoline burned, multiplied by gallons consumed per year. EV CO2 uses the EIA national average grid emission factor of 0.386 kg of CO2 per kWh, multiplied by annual kWh consumed. The difference is the annual CO2 reduction. In states with cleaner electricity grids (hydro, wind, solar heavy), the EV's CO2 will be even lower.
Are maintenance costs lower for EVs?
Yes, EVs generally have lower maintenance costs than gas cars because they have fewer moving parts. EVs do not require oil changes, have no transmission fluid, no spark plugs, and regenerative braking reduces brake pad wear. Consumer Reports and the US Department of Energy estimate EV maintenance costs are 30 to 40 percent lower than equivalent gas vehicles over a vehicle's lifetime. This calculator covers fuel costs only; maintenance savings add further to the EV's financial advantage.
Official sources
- EPA Fuel Economy Guide: fueleconomy.gov.
- EPA GHG Equivalencies Calculator: epa.gov/energy/greenhouse-gas-equivalencies-calculator.
- EIA Electric Power Annual: eia.gov/electricity/annual.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. General information only, not financial advice.